Device for automatic self-levelling of the body of a threshing-harvesting machine

ABSTRACT

Automatic self-levelling of the body of a threshing-harvesting machine is effected by a device which is sensitive to the operation of respective magnetic float switches located in respective interconnected liquid-containing vessels positioned on opposite lateral sides of the body. Each vessel contains two laterally spaced apart float switches connected to electro-valves in an hydraulic circuit for self-levelling actuators so that when either of the laterally outer float switches is operated the actuators are supplied with part of the hydraulic fluid output from a pump to effect correction and when either of the inner switches is operated at a greater angle of inclination, the actuators are supplied with the full pump output to effect rapid levelling. An alarm is operated automatically in the event of excessive inclination of the body of the machine.

United States Patent Laverda DEVICE FOR AUTOMATIC SELF- LEVELLING OF THEBODY OF A THRESHING-HARVESTING MACHINE Inventor: Pietro Laverda,Breganze, Italy Pietro Laverda S.p.A., Breganze, Italy Filed: June 11,1971 Appl. No.: 152,144

Assignee:

Int. Cl ..B60g 17/04 Field of Search ..280/6, 6 H, 6.1, 6.11, 124 FReferences Cited UNITED STATES PATENTS 2/1966 Boone ..-....280/6 H8/1966 Allinquant ..280/6 H [451 Nov. 21, 1972 3,181,878 5/1965 Vogel..280/6.l

Primary ExaminerPhilip Goodman Attorney-Sughrue, Rothwell, Mion, Zinn &Macpeak ABSTRACT Automatic self-levelling of the body of athreshingharvesting machine is effected by a device which is sensitiveto the operation of respective magnetic float switches located inrespective interconnected liquidcontaining vessels positioned onopposite lateral sides of the body. Each vessel contains two laterallyspaced apart float switches connected to electro-valves in an hydrauliccircuit for self-levelling actuators so that when either of thelaterally outer float switches is operated the actuators are suppliedwith part of the hydraulic fluid output from a pump to effect correctionand when either of the inner switches is operated at a greater angle ofinclination, the actuators are supplied with the full pump output toeffect rapid levelling. An alarm is operated automatically in the eventof excessive inclination of the body of the machine.

3 Claims, 3 Drawing Figures PATENTED I97? 3. 703, 298

sum 1 or 3 INVENTOR P/E m0 LAvEmA 53 k, n, BY 2' wc hk ATTORNEYSPATENTEWZL I912 SHEET 3 0F 3 3.703.298

mm mm DEVICE FOR AUTOMATIC SELF-LEVELLING OF THE BODY OF ATHRESHING-IIARVESTING MACHINE BACKGROUND OF THE INVENTION This inventionrelates to a device for effecting automatic levellingthreshing-harvesting machines.

It is known to provide such machines with devices which maintain thebody of the threshing machine upright independently of unevenness of theground on which the wheels of the machine rest.

The body of such machines is hinged in its center for rocking movementabout axles which are formed by double levers interconnected indeformable parallelogram linkages, the body being kept upright byhydraulic double-acting rams.

The cutting platform of the machine is kept substantially parallel tothe ground by means of other devices which form a connection between theplatform itself and the front axle of the machine.

An object of this invention is to provide a device for the automaticlevelling of the body of such machines, which is of simple, strong andeconomical construction, precise and safe in operation and of highfunctional efficiency.

Another object of this invention is to provide a device of the abovementioned type, which allows automatic levelling at different rates as afunction of the inclination taken of the body to the horizontal andwhich allows at the same time manual emergency operation for quickstraightening.

A further object of this invention is to provide a device as aforesaidwhich has high sensitivity and precision of control and is able to ceaseoperation immediately in the event of an excessive inclination of thebody to the horizontal, initiating an alarm signal.

SUMMARY OF THE INVENTION The present invention accordingly provides adevice for effecting automatic levelling of the body of athreshing-harvesting machine, characterized in that the device comprisestwo inter-communicating liquid-containing vessels, mounted on oppositelateral sides of the body, first and second magnetic level-sensitiveswitches placed at different lateral positions or heights in each vesseland adapted to operate selectively in response to lateral inclinationsof the body of the machine to the horizontal by more than a first andmore than a second angle respectively, the second angle being greaterthan the first, the first switches being arranged to operate a doubleacting first electro-valve in a feed circuit for two hydraulic levellingactuators and the second switches being arranged to operate a secondelectro-valve,

which normally reduces the flow of hydraulic fluid under pressure from apump to the actuators so that the latter are supplied with the full pumpflow to eflect rapid levelling, means for operating the two electro--valves manually and means operative to prevent the two electro-valvesfrom operating in the event of an excessive inclination of the saidbody, and to activate an alarm device.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described,by way of nonlimiting example, with reference to the accompanyingdrawings, in which:

FIG. 1 is a schematic front view of a threshing-harvesting machineprovided with an automatic body levelling device according to oneembodiment of the invention;

FIG. 2 is an hydraulic circuit diagram of the device, and

FIG. 3 is an electric circuit diagram of the device.

DETAILED DESCRIPTION OF THE DRAWINGS With referenceto FIG. '1, referencenumeral 1 indicates the body of a threshing-harvesting machine (drawnwithout its cutting platform). The body 1 has a central front appendagela which is pivotally connected to a front axle 3 by means of a centerpivot 2 for rocking movement about a central longitudinal axis.

The body 1 is formed with two lateral brackets 4, 4 which providepivotal support for the cylinders 5, 5 of the respective hydraulicdouble-acting rams, the piston rods 6, 6' of which are pivotallyconnected by means of respective joints 7, 7' to opposite ends of theaxle 3.

As illustrated in FIG. 2, the ram cylinders 5, 5' are supplied from anhydraulic pump 8, which draws hydraulic fluid from a tank 9 and suppliesthe fluid under pressure, through an adjustable spring-loaded pressurerelief valve 10, to a conduit 11 which subdivides into two branchconduits 12 and 13. The branch conduit 12 supplies the fluid underpressure to a double-acting first solenoid-operated electrovalve 14. Thevalve 14 has a first pair of output conduits 15, 15' connected toopposite ends of the respective cylinders 5, 5' and a second pair ofoutput conduits 16, 16 connected to the other ends of said cylinders, sothat the conduits 15 and 16' are connected to the lower ends of thecylinders 5 and 5 and the conduits 15' and 16 are connected to the upperends of the cylinders 5' and 5 respectively.

The branch conduit 13 is connected through an adjustable flow restrictor17 to a single-acting second solenoid-operated electro-valve' 19 which,in its rest condition, connects the output of the restrictor 17 to thetank 9 to ensure that substantially half the output flow from the pump 8reaches the first electro-valve 14.

FIG. 3 illustrates the electric circuit of the device. Twointer-communicating vessels 19, 19' are fixed laterally to the body 1 ofthe machine and communicate through aconduit 19a containing a throttlingvalve 19b. Each vessel 19 and 19 contains two magnetically operatedfloat switches 20, 21 and 20', 21' respectively co-operating withrespective magnetic relays 22, 23 and 22', 23. The two switches 20, 21and 20, 21' in each vessel 19 and 19 are spaced apart laterally so thatthe two outermost switches 20 and 20 are more sensitive to lateralinclination of the body 1 than the two innermost switches 21 and 21'.Alternatively, the two switches 20, 21 and 20', 21 may be arranged atdifferent heights in each vessel.

Current is supplied through a lead 24, a fuse 24a and a master switch 25to a pilot lamp 26, a relay 27 and an interruptor 28 connected in itsturn with a flasher lamp 29 and an optical and acoustic alarm device 30.

A micro-switch 31 is operable manually by means of an emergency lever32, pivoted at 33 and adapted to act mechanically on the double-actingfirst electrovalve 14. Two limit micro-switches 34, 34' are arranged tobe operated directly by the axle 3 when the lateral inclination of thebody 1 exceeds the maximum inclination at which the automatic controldevice is allowed to operate.

The operation of the device is as follows:

When the body 1 of the machine reaches a lateral inclination to thehorizontal between 4 and l the lower of the two laterally outer floatswitches 20 and 20' is operated by the buoyancy effect ofthe liquid inthe vessel 19 or 19 to close the circuit in which it is connected andoperate the first electro-valve 14 so as to cause the latter to directthe hydraulic fluid into opposite ends of the two cylinders S and 5 in asense such as to counter the inclination of the body 1 of the machineand thereby bring about levelling of the latter. The flow of fluid intothe two ram cylinders 5, 5' is substantially half the output flow of thepump 8, and therefore the levelling speed is slow.

When the body 1 of the machine has reached an upright position, thefloat switch which has been operated reopens the circuit and-thelevelling action of the device stops.

The fluid transfer rate from one vessel to the other is controlled bythe throttling valve 21 so that the damping action of the liquid allowsthe body of the machine to reach an exactly upright position and not aposition inclined to the horizontal.

When the body 1 of the machine assumes an inclination to the horizontalgreater than both magnetic float switches and 21 or 20' and 21' whichare in the lower vessel 19 or 19' close, energizing simultaneously boththe electro-valves l4 and 18. The electro-valve l8 closes the returnfluid path through the flow-restrictor 17 to the tank 9 and thereforethe entire output of the pump 8 will pass through the electro-valve 14and will be supplied to the cylinders 5 and 5'. The latter then causerapid levelling of the body of the machine. When the inclination of thebody 1 is again smaller than 10, the laterally inner float switch (23,or 23') is reopened and the second electro-valve 18 therefore againopens, reducing the rate of levelling.

When the inclination of the machine body to the horizontal has reachedthe maximum limit of safety, the axle 3 operates one of the limitswitches 34 and 34, so that the relay 27 is energized, causing operationof the interruptor 28 and therefore of the optical and acoustic alarmdevice 30 and the flasher lamp 29. As the same time the current is cutoff from the relays 22, 23, 22', 23 of the float switches and so the twoelectro-valves 14 and 18 remain in their rest positions and thehydraulic circuit is inoperative. Automatic levelling control thereforeceases.

The first electro-valve 14 can also be controlled manually by means ofthe emergency lever 32, which acts mechanically on the moving part ofthe valve 14 and which also operates the micro-switch 31 so as tointerrupt the current which would normally be supplied to the relays 22,and 22 by the inner float switches 20 and 20' supplying this currentdirectly to the electrovalve 18, which causes the entire output flowfrom the pump 8 to reach the first electrovalve 14, allowing rapidlevelling of the body 1 of the machine, as previously described, as ifone of the inner float switches 23,

24' has been operated. It will be appreciated that details of practicalembodiments of this invention may depart widely from the illustratedembodiment without departing from the scop of this invention.

I c arm:

1. Device for effecting automatic levelling of the body of athreshing-harvesting machine, comprising in combination:

a. two liquid-containing vessels mounted on opposite lateral sides ofthe body;

b. conduit means intercommunicating said vessels;

c. first and second magnetic level-sensitive switches in each respectivevessel, said two switches being located at different lateral positionsin each vessel and being operable selectively in response to lateralinclinations of said body of the machine to the horizontal by more thana first and a second angle respectively, the second angle being greaterthan the first;

. a double acting first electro-valve operable by the first switches;

. an hydraulic circuit including two hydraulic levelling actuators, saidfirst electro-valve being included in said circuit and controllingsupply of hydraulic fluid thereto;

f. a pump in said hydraulic circuit;

g. a second electro-valve operable by the second switches, said secondelectro-valve normally reducing the flow of hydraulic fluid underpressure from said pump to the actuators, the latter being supplied withthe full pump flow to effect rapid levelling when 7 said secondelectro-valve is operated by said second switches,

h. means operating said two electro-valves manually;

i. means sensitive to excessive inclination of said body to thehorizontal to prevent said two electrovalves from operating, and,

j. an alarm device operable by said means sensitive to excessiveinclination.

2. Device according to claim 1, wherein said manual control means foroperating the two electro-valves comprise a lever arranged to actmechanically on the movable part of the first electro-valve andincluding an electric switch operable simultaneously by said lever tooperate said second electro-valve so that the entire output flow of saidpump is supplied to said levelling actuators for rapid levelling.

3. Device according to claim 1, wherein said means to prevent said twoelectro-valves from operating and for activating said alarm device areformed by two limit switches arranged to be operated mechanically by anaxle of the machine when the body of the machine exceeds a maximumpredetermined inclination to the horizontal, a relay connected to saidlimit switches, an interruptor connected to said relay and operable uponenergization thereof, and an optical and acoustic alarm device connectedto the interruptor for operation thereby in response to operation ofeither limit switch, said limit switches upon operation also breakingthe electric circuits of said two electro-valves.

1. Device for effecting automatic levelling of the body of athreshing-harvesting machine, comprising in combination: a. twoliquid-containing vessels mounted on opposite lateral sides of the body;b. conduit means intercommunicating said vessels; c. first and secondmagnetic level-sensitive switches in each respective vessel, said twoswitches being located at different lateral positions in each vessel andbeing operable selectively in response to lateral inclinations of saidbody of the machine to the horizontal by more than a first and a secondangle respectively, the second angle being greater than the first; d. adouble acting fIrst electro-valve operable by the first switches; e. anhydraulic circuit including two hydraulic levelling actuators, saidfirst electro-valve being included in said circuit and controllingsupply of hydraulic fluid thereto; f. a pump in said hydraulic circuit;g. a second electro-valve operable by the second switches, said secondelectro-valve normally reducing the flow of hydraulic fluid underpressure from said pump to the actuators, the latter being supplied withthe full pump flow to effect rapid levelling when said secondelectro-valve is operated by said second switches; h. means operatingsaid two electro-valves manually; i. means sensitive to excessiveinclination of said body to the horizontal to prevent said twoelectro-valves from operating, and, j. an alarm device operable by saidmeans sensitive to excessive inclination.
 1. Device for effectingautomatic levelling of the body of a threshing-harvesting machine,comprising in combination: a. two liquid-containing vessels mounted onopposite lateral sides of the body; b. conduit means intercommunicatingsaid vessels; c. first and second magnetic level-sensitive switches ineach respective vessel, said two switches being located at differentlateral positions in each vessel and being operable selectively inresponse to lateral inclinations of said body of the machine to thehorizontal by more than a first and a second angle respectively, thesecond angle being greater than the first; d. a double acting fIrstelectro-valve operable by the first switches; e. an hydraulic circuitincluding two hydraulic levelling actuators, said first electro-valvebeing included in said circuit and controlling supply of hydraulic fluidthereto; f. a pump in said hydraulic circuit; g. a second electro-valveoperable by the second switches, said second electro-valve normallyreducing the flow of hydraulic fluid under pressure from said pump tothe actuators, the latter being supplied with the full pump flow toeffect rapid levelling when said second electro-valve is operated bysaid second switches; h. means operating said two electro-valvesmanually; i. means sensitive to excessive inclination of said body tothe horizontal to prevent said two electro-valves from operating, and,j. an alarm device operable by said means sensitive to excessiveinclination.
 2. Device according to claim 1, wherein said manual controlmeans for operating the two electro-valves comprise a lever arranged toact mechanically on the movable part of the first electro-valve andincluding an electric switch operable simultaneously by said lever tooperate said second electro-valve so that the entire output flow of saidpump is supplied to said levelling actuators for rapid levelling.